The subjects of this study were 258 Korean-Chinese parent-child dyads of an elementary school in Yanbian Province, northeastern China. Research questions covered relationships among children`s school adjustment and ecological factors, significance of factors within ecological levels, and direct and indirect effects in causal relationships. Results showed significant effects within each ecological level. Achievement motivation of the individual system, home environment and social support of the microsystem, and mother`s job satisfaction in the exosystem had significant relationships with children`s school adjustment. Mother`s education and job satisfaction influenced school adjustment through home environment; the causal relationship between social support and school adjustment was mediated by achievement motivation. Personal and general factors from each ecological level were more significant than ethnic related factors in explaining children`s school adjustment.